Alkenyl succinic acid anhydride type compounds may be typically prepared by the reaction of a polyisobutene and maleic acid anhydride, in the presence of catalyst such as 1,3-dibromo-5,5-dialkyl hydantoin. It is found however that the reaction mixture contains undesirable sludge in amount as high as 6-7 w % or more.
It is an object of this invention to provide a process for preparing alkenyl succinic acid anhydrides in the presence of catalyst which permits operation characterized by formation of decreased amounts of sludge. Other objects will be apparent to those skilled in the art.